Offer Grok Build as a skill install target

README.md

@@ -17,7 +17,7 @@
 
 `fizzy` is a command-line interface for [Fizzy](https://fizzy.do). Manage boards, cards, comments, and more from your terminal or through AI agents.
 
-- Works standalone or with any AI agent (Claude, Codex, Copilot, Gemini)
+- Works standalone or with any AI agent (Claude, Codex, Copilot, Gemini, Grok)
 - JSON output with breadcrumbs for easy navigation
 - Token authentication via personal access tokens
 - Includes agent skill and Claude plugin setup

internal/commands/skill.go

@@ -31,6 +31,7 @@ var skillLocations = []SkillLocation{
 	{Name: "OpenCode (Global)", Path: "~/.config/opencode/skill/fizzy/SKILL.md"},
 	{Name: "OpenCode (Project)", Path: ".opencode/skill/fizzy/SKILL.md"},
 	{Name: "Codex (Global)", Path: codexGlobalSkillPath()},
+	{Name: "Grok (Global)", Path: grokGlobalSkillPath()},
 }
 
 var skillCmd = &cobra.Command{
@@ -257,11 +258,21 @@ func normalizeSkillPath(path string) string {
 }
 
 func codexGlobalSkillPath() string {
-	codexHome := strings.TrimSpace(os.Getenv("CODEX_HOME"))
-	if codexHome == "" {
-		return "~/.codex/skills/fizzy/SKILL.md"
+	return agentGlobalSkillPath("CODEX_HOME", "~/.codex")
+}
+
+func grokGlobalSkillPath() string {
+	return agentGlobalSkillPath("GROK_HOME", "~/.grok")
+}
+
+// agentGlobalSkillPath locates the skill under an agent's home directory:
+// homeEnv when set, otherwise homeDir.
+func agentGlobalSkillPath(homeEnv, homeDir string) string {
+	home := strings.TrimSpace(os.Getenv(homeEnv))
+	if home == "" {
+		return homeDir + "/skills/fizzy/SKILL.md"
 	}
-	return filepath.Join(codexHome, "skills", "fizzy", skillFilename)
+	return filepath.Join(home, "skills", "fizzy", skillFilename)
 }
 
 // expandSkillPath expands ~ to home directory.

internal/commands/skill_test.go

@@ -87,6 +87,31 @@ func TestExpandSkillPath(t *testing.T) {
 	}
 }
 
+func TestAgentGlobalSkillPath(t *testing.T) {
+	tests := []struct {
+		name   string
+		env    string
+		envVal string
+		path   func() string
+		want   string
+	}{
+		{"codex default", "CODEX_HOME", "", codexGlobalSkillPath, "~/.codex/skills/fizzy/SKILL.md"},
+		{"codex override", "CODEX_HOME", "/opt/codex", codexGlobalSkillPath, filepath.Join("/opt/codex", "skills", "fizzy", "SKILL.md")},
+		{"codex blank override", "CODEX_HOME", "  ", codexGlobalSkillPath, "~/.codex/skills/fizzy/SKILL.md"},
+		{"grok default", "GROK_HOME", "", grokGlobalSkillPath, "~/.grok/skills/fizzy/SKILL.md"},
+		{"grok override", "GROK_HOME", "/opt/grok", grokGlobalSkillPath, filepath.Join("/opt/grok", "skills", "fizzy", "SKILL.md")},
+		{"grok blank override", "GROK_HOME", "  ", grokGlobalSkillPath, "~/.grok/skills/fizzy/SKILL.md"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Setenv(tt.env, tt.envVal)
+			if got := tt.path(); got != tt.want {
+				t.Errorf("%s = %q, want %q", tt.name, got, tt.want)
+			}
+		})
+	}
+}
+
 func TestInstallSkillFiles(t *testing.T) {
 	home := t.TempDir()
 	t.Setenv("HOME", home)